This invention relates to musical instruments, to guitars, and more specifically to guitars equipped with a tremolo device for dynamically altering the pitch of the instrument.
There are many tremolo devices of many different configurations known to those skilled in the musical instruments arts. All tremolo devices, except that designed and patented by Floyd Rose, U.S. Pat. No. 4,171,661, have the common fault that use of the tremolo device or even merely playing the instrument with a tremolo device will alter the pitch of said instrument.
The Floyd Rose patent, U.S. Pat. No. 4,171,661, describes a technique for fixing the pitch of the instrument by clamping the strings at the bridge and the nut at the end of the neck. These clamps produce a large friction force between the guitar and the strings. Although the Rose design is effective in maintaining the pitch of the instrument, it requires a complex tuning procedure of loosing clamps at the nut, retuning, and reclamping.
There are many tuning peg designs. Of particular note are designs patented by G. B. Durkee, U.S. Pat. No. 554,057, and Kluson, U.S. Pat. No. 2,557,877. Both of these patents disclose means for attaching or clamping the string to the tuning peg shaft. Another tuning device which clamps the string is presented by Mullen, U.S. Pat. No. 4,141,271. This device undesirably requires tools to operate because the spacing between tuning members is very small.
There are also many tremolo bridge designs. The most notable was patented by C. L. Fender, U.S. Pat. No. 2,741,146. Although this design has an excellent tremolo sound and operational feel, the bridge does permit the instrument to go out of tune for many reasons. The pivoting means prohibits the bridge from returning to its exact original location, the bridge saddles move and alter the pitch of the instrument, and the saddles present a significant medium friction force on the string which also can alter said pitch.
The definition of a medium friction force is one which is large enough to impede noticeably the motion of the string but insufficient to halt the motion of the string in all situations. A high friction force is then one which is sufficient to stop motion under all conditions, such a friction is produced by a clamp. Conversely, a low friction force is one which does not noticeably affect the motion.
There are many adjustable bridge patents in the art, for example two by C. L. Fender, U.S. Pat. Nos. 2,741,146 and 4,281,576. These bridge disclosures describe bridges which permit independent height and intonation adjustment of every string. Practical experience has shown that this flexibility is not necessarily needed with proper string sizing and bridge design.
Practical experience also has shown that bridges generally are not sufficiently stiff and are not stable. The lack of rigidity detrimentally affects the sound and sustain of the instrument. The instability in the string adjustments generally requires complex readjustment too frequently.
Additionally there are patents which incorporate rollers to minimize the friction between the string and the contact. An example of this art is Mullen, U.S. Pat. No. 4,141,271. However, the roller presented by Mullen is simply mounted on a shaft and is subject to being driven along the shaft. Any side motion detrimentally affects the sustain and sound of the instrument.
Furthermore, there are a number of techniques in the art for attaching a bead on the bridge end of the string for simple attachment to the instrument. Examples of this art are D. L. Mari, U.S. Pat. No. 3,313,196 and W. N. Stone, et al., U.S. Pat. No. 4,164,806.